A BBC journalist has apologised after disparaging comments made about one of the victims killed in Saturday’s helicopter crash alongside Leicester City owner Vichai Srivaddhanaprabha.

Sports editor Dan Roan caused outrage among fans when his off-air conversation with a producer was picked up by a Sky News live feed outside the King Power Stadium, where thousands of fans had left tributes and flowers at a memorial to mark the crash site.

Roan was filmed referring to married father-of-four Srivaddhanaprabha’s personal assistant Nusara Suknamai, a former Thai beauty queen, as the billionaire owner’s “mistress”.

“As opposed to the mistress who died in the crash, otherwise known as member of staff, i.e. mistress ... family man ...” Roan said.

He added: “But that’s what you do if you are a billionaire or royalty, it’s relatively expected so we shouldn’t judge.”

Suknamai was killed when the aircraft plummetted 200 feet and crash-landed in the car park outside the stadium soon after taking off from the centre circle of the pitch, following Leicester’s 1-1 home draw against West Ham.

She died along with her 60-year-old boss, fellow employee Kaveporn Punpare, and pilot Eric Swaffer and his partner Izabela Roza Lechowicz, who was also a pilot.

Srivaddhanaprabha’s family paid their respects at the site of the crash on Monday, along with Leicester’s players and thousands of fans.

“Just want to say sorry for some comments made in a private, off-air conversation earlier with a colleague,” Roan tweeted on Monday. “Absolutely no offence intended.”

A BBC spokesman also apologised for the comments by senior journalist Roan, who has been sports editor of the BBC since September 2014 following stints as sports news correspondent and chief sports correspondent.

“This was an ill-judged comment made in a private off-air conversation for which Dan has apologised,” the spokesman said.

But fans were quick to criticise the journalist for his remarks.

“It doesn’t matter that it was private, or off-air, you were stood 5 yards away from his memorial,” wrote one Leicester fan in response to Roan’s tweet.

“So disrespectful, so thoughtless and hurtful. You should be ashamed. Please don’t come anywhere near my football club again.”

A Leicester City fan account said: “You’re only sorry you was caught. Please don’t ever return to our club, you’re most definitely not welcome.”

Another Twitter user wrote: “Classless and completely unprofessional. Just made worse by where you were at the time. If this was a sportsman that made it you’d be skewering him as we speak.”